're involved in a firefight with the taliban in afghanistan. and there you see an m-240-b gunner that they're using against the taliban. as they're talking to each other, giving each other directions, listen to this. >> oh. >> one of the bullets from the taliban goes right over these guys' heads and you can hear it. >> oh, my goodness, wow. >> did you hear how close that was. >> whizzed right over. >> it almost feels like it ricochets off the camera. you hear a pop, a snap like it hits something close by. >> that pop, that crack is known as bullet shock wave and a eaet when it dib travels at supersonic speed. >> this is a day at work. you're having a bad day at your job, watch this. >>> only two brothers would get themselves in a scenario that looks like this. >> look at his skin. look at his ears. look at everything. >> what? >> yeah, nice. >> stop it, cole! >> oh! >> get off. >> okay. >> that is a bunch of like packing tape wrapped around his brother jack's face, hair, head and hands. brother paul kennedy did this to him. >> this does seem like something siblings would do to each other.